This invention relates to a semiconductor manufacturing method and, more particularly, to a method of manufacturing a semiconductor laser having an internal current restriction by using e.g. molecular-beam epitaxy.
A conventional AlGaAs/GaAs semiconductor laser having an internal current restriction is manufactured by growing a layer of one conductivity type on a substrate of the opposite conductivity type by a first crystal growth step, etching away a portion of this layer in a stripe-shaped configuration, and growing a double heterojunction on the substrate in a second crystal growth step in such a manner that the stripe can be provided with a current path.
However, problems with this conventional semiconductor laser manufacturing method are that the crystal growth step is required to be performed twice, and flaws tend to develop at the interface of the first and second growths, which serves as a reverse bias current blocking layer, since the substrate is exposed to high temperatures at the time of the second growth step.